Alonso says F1 power unit probably underestimated Mexico City altitude challenge

Fernando Alonso believes the power unit probably underestimated the altitude challenge at the Mexico City Grand Prix. He and Aston Martin team-mate Lance Stroll both retired after five laps. Alonso said he recognised it as a shared problem when Stroll’s car also retired; Aston Martin described abnormal pressure levels in the power-unit systems.

A water-pressure issue cut Alonso’s qualifying short: he was told to stop after one flying lap. He believed the car could have challenged for a strong Q2 result and said the three practice sessions had gone well. His seventh place in FP1 was Aston Martin’s best session result of the season.

Mexico City sits 2,285 metres above sea level, where air density is around 20% lower than at sea level. The turbos must work harder to deliver the power drivers demand, while the 2026 power units no longer include the MGU-H, a component that helped eliminate turbo lag.

Alonso called the retirements part of the learning process and said he hoped the team could take hard lessons from the weekend.